At present, known shock-absorbing materials include air-cell cloth as well as foam rubber and plastic. The air-cell cloth comprises two layers, one upper and one lower, heat-sealed together at their circumferential edge. A plurality of air cells is contained and bulges between the two layers. Each air cell is empty, but has an atmospheric pressure, which can function as a shock-aborber, as the atmospheric pressure generates an anti-shock force when it receives an exterior pressure because of the principle P1.V1=P2.V2. Nevertheless, the inner pressure of the air-cell cloth is constant, and every air cell does not communicate with each other, having the following disadvantages.
1. Each air cell in the common conventional air-cell cloth has a constant inner pressure so that its shock-absorbing effect is also constant, and is impossible to be changed to cope with different circumstances.
2. Most air-cell cloth is made to have a flat surface. If any of the air cells should be damaged or broken, it could not be repaired, thereby impairing the shock-absorbing effect.
3. Most air-cell cloth is flat, rendering it impossible to be directly used for three-dimensioned things, except for folding it around them.
4. Most air-cell cloth is provided with independent air cells not communicating with one another so that the inner pressure of the cloth is not adjustable according to necessity, thereby restricting its use.